Rebecca S. Lufler

Incorporating radiology into medical gross anatomy: Does the use of cadaver CT scans improve students' academic performance in anatomy?

Radiological images show anatomical structures in multiple planes and may be effective for teaching anatomical spatial relationships, something that students often find difficult to master. This study tests the hypotheses that (1) the use of cadaveric computed tomography (CT) scans in the anatomy laboratory is positively associated with performance in the gross anatomy course and (2) dissection of the CT‐scanned cadaver is positively associated with performance on this course. One hundred and seventy‐nine first‐year medical students enrolled in gross anatomy at Boston University School of Medicine were provided with CT scans of four cadavers, and students were given the opportunity to choose whether or not to use these images. The hypotheses were tested using logistic regression analysis adjusting for student demographic characteristics. Students who used the CT scans were more likely to score greater than 90% as an average practical examination score (odds ratio OR 3.6; 95% CI 1.4, 9.2), final course grade (OR 2.6; 95% CI 1.01, 6.8), and on spatial anatomy examination questions (OR 2.4; 95% CI 1.03, 5.6) than were students who did not use the CT scans. There were no differences in performance between students who dissected the scanned cadavers and those who dissected a different cadaver. These results demonstrate that the use of CT scans in medical gross anatomy is predictive of performance in the course and on questions requiring knowledge of anatomical spatial relationships, but it is not necessary to scan the actual cadaver dissected by each student. Anat Sci Educ 3: 56–63, 2010.

Frontalis midline dehiscence: an anatomical study and discussion of clinical relevance.

HYPOTHESIS The frontalis muscle has a midline dehiscence that has not been well described. The anatomic characteristics of the muscles of the central forehead are important to effectively treat rhytids in this area, e.g. with botulinum toxin. METHODS Anatomical dissections of 21 cadaver foreheads. RESULTS For males, the midline attenuation point occurred in a range from 1.4 to 6 cm above the horizontal orbital rim plane, with the mean being 3.5+/-1.6 cm. The mean angle of the left muscle belly in the male cadavers was 26.0+/-17.4 degrees off the midline, while the right was 36.4+/-14.9 degrees. Overall average angulation was 62.4 degrees (Figure 4). The mean distances between left and right muscle bellies at 4 cm, 5 cm and 6 cm superior to the orbital rim were 1.2 cm, 1.9 cm and 3.1 cm, respectively. The mean distance of dehiscence in the midline from the horizontal reference plane of the female cadavers was 3.7+/-1.8 cm, with a range of 1.3 to 6.0 cm. The left frontalis belly formed an angle with the midline of 15.9+/-16.6 degrees, while the right belly formed an angle of 22.3+/-20.1 degrees, with an overall average angle of 38.2 degrees. The interbelly distances at 3, 4, 5 and 6 cm were 0.4 cm, 0.9 cm, 1.7 cm and 2.6 cm, respectively. One third of females had no midline frontalis dehiscence at 6 cm above the orbital rims. CONCLUSIONS The anatomic characterization of the midline frontalis muscle dehiscence permits more intelligent placement of chemotherapeutic agents when treating forehead rhytids.

Imaging the cadavers being dissected does not appear to improve the gross anatomy dissection experience

In their Letter to the Editor entitled “Are computed tomography scans of cadavers perceived as a useful educational adjunct in a surgical anatomy course?” Cornwall and Stringer argue that incorporating CT scans of the actual cadavers being dissected is of limited value in a surgical anatomy course (Cornwall and Stringer, 2014). The authors of this letter cite our study (Lufler et al., 2010), in which we examined the utility of providing CT scans of some of the cadavers being dissected in a large first-year medical gross anatomy course. Despite numerous methodological differences, the conclusions of both studies are consistent with each other. In the study by Lufler et al. (2010), we provided the CT scans of four of the 22 bodies being dissected in the first year medical gross anatomy course. All students had access to the scans, but only 18% of the students dissected the bodies that had been scanned. Individual student use of the scans was tracked by requiring that individuals log in to the computers in order to access the scans. The results of that study demonstrated that those individuals who used the scans performed more strongly on numerous measures of academic performance in the course. However, there were no differences in performance between students who dissected the specific cadaver that was scanned and those that dissected one of the other bodies. Despite being targeted at different populations (first-year undergraduate medical students versus surgical residents) and having used different methods of assessment (examination grades versus surveys), our study and that of Cornwall and Stringer find similar conclusions. Namely, making available the scans of the actual cadavers being dissected does not seem to impart any benefit beyond that of providing a generic CT scan. However, the methodological differences between the studies should be emphasized. Unlike Cornwall and Stringer, we did not solicit any feedback from the students to determine how they perceived the CT scans educationally. It is possible that the students who used the CT scans in our study felt that this practice was educationally useful, even if their examination scores later proved to be indistinguishable from those of their peers. Because of the different methodologies it is difficult to directly compare the results of these two studies. Both sets of authors also make the caveat that this conclusion may change if trainees are required to correlate their dissections with their scans in some way. The students’ use of the CT scans in both of these studies was optional and self-directed. It has been shown that self-directed learning principles can elicit mixed feedback from students on their educational value (Bergman et al., 2013). In our study, students with kinesthetic learning styles were most likely to use the scans, indicating that selfdirected use of scans in the laboratory may only be appealing to a subset of the trainees. Given any lack of concrete purpose for the scans, it is not surprising that there was no obvious benefit to being able to correlate the scans to particular cadavers. However, it is not difficult to imagine educational scenarios in which it would be very useful to be able to correlate cadaverspecific CT scans with the students’ dissection activities. For example, Bohl et al. (2011) describe the use of web-based, selfguided clinical cases based on findings in postmortem CT scans of the cadavers in their first-year undergraduate course. Similarly, Jacobson et al. (2009) describe the creation of “virtual patients” from the CT scans of the cadavers in their laboratory. The pathological findings from the CT images were used to develop plausible clinical cases designed to highlight and explain the abnormal anatomic findings encountered during the cadaveric dissection. In both of these studies, students were encouraged but not required to use these cases. However, with little additional work, tasks could be designed that require the students dissecting the scanned cadavers to use these virtual patients’ findings to prospectively guide their dissections, especially in the context of interesting pathologies or anomalies. In conclusion, Cornwall and Stringer (2014) generally agree with our conclusions by Lufler et al. (2010) that there is limited utility of providing the CT scans of the actual cadavers being dissected. It is reasonable to postulate that activities could be designed that would increase the utility of scanning the actual bodies being dissected. However, the pedagogical benefit of such activities must be weighed against the significant financial and time expenses required to acquire the scans and produce the corresponding educational tasks every year. Although the benefit of scanning the same donors may be limited, evidence does support a robust educational benefit of providing generic high quality radiological images in the gross anatomy laboratory.

Anatomical origin of forefoot varus malalignment.

BACKGROUND Forefoot varus malalignment is clinically defined as a nonweightbearing inversion of the metatarsal heads relative to a vertical bisection of the calcaneus in subtalar joint neutral. Although often targeted for treatment with foot orthoses, the etiology of forefoot varus malalignment has been debated and may involve an unalterable bony torsion of the talus. METHODS Forty-nine feet from 25 cadavers underwent bilateral measurement of forefoot alignment using adapted clinical methods, followed by dissection and measurement of bony talar torsion. The relationship between forefoot alignment and talar torsion was determined using the Pearson correlation coefficient. RESULTS Mean ± SD forefoot alignment was -0.9° ± 9.8° (valgus) and bony talar torsion was 32.8° ± 5.3° valgus. There was no association between forefoot alignment and talar torsion (r = 0.18; 95% confidence interval, -0.11 to 0.44; P = .22). CONCLUSIONS These findings may have implications for the treatment of forefoot varus since they suggest that the source of forefoot varus malalignment may be found in an alterable soft-tissue deformity rather than in an unalterable bony torsion of the talus.

The Association of Forefoot Varus Deformity with Patellofemoral Cartilage Damage in Older Adult Cadavers

Forefoot alignment may contribute to patellofemoral joint (PFJ) osteoarthritis (OA) via its influence on the closed chain kinematics of the lower limb. The purpose of this cadaveric study was to investigate the relationship between forefoot varus and ipsilateral cartilage damage in the medial and lateral PFJ. Forefoot alignment measurements were obtained from the feet of 25 cadavers (n = 50). Cartilage damage in the medial and lateral PFJ of each knee was scored using the Outerbridge scale. The relative odds of medial and lateral PFJ cartilage damage in limbs with forefoot varus and valgus were determined using logistic regression. The relationship between increasing varus alignment and increasing odds of medial and lateral PFJ cartilage damage was assessed. Of the 51% of limbs with forefoot varus, 91.3% had medial, and 78.3% had lateral PFJ cartilage damage, compared with 54.6% and 68.2% of those with forefoot valgus. The former also had 3.0 times (95% CI 1.2, 7.7) the odds of medial PFJ damage; no association was found with lateral damage (OR 1.4, 95% CI 0.7, 3.0). Feet in the highest tertile of varus alignment had 3.9 times (95% CI 10, 15.3, P = 0.058) the odds of medial PFJ damage as those in the lowest tertile. The results of this study suggest a relationship between forefoot varus and medial PFJ cartilage damage in older adults. As forefoot varus may be modified with foot orthoses, these findings indicate a potential role for orthoses in the treatment of medial PFJ OA. Anat Rec, 300:1032–1038, 2017.